Wireless tag detection apparatus and method of controlling the same

Abstract

Query signals to one or more wireless tags are transmitted via radio communication, and a distance to a wireless tag to be retrieved is informed according to strength of a response signal from the wireless tag to be retrieved, which is included in the response signals transmitted from the one or more wireless tags via radio communication.

1. A wireless tag detection apparatus comprising:
 transmission means for transmitting query signals to one or more wireless tags via radio communication; 
 reception means for receiving one or more response signals transmitted via radio communication from the one or more wireless tags based on query signals transmitted via radio communication from the transmission means; 
 specification means for specifying a wireless tag to be retrieved; 
 extraction means for extracting tag identification information corresponding to the wireless tag specified by the specification means; 
 selection means for selecting a response signal containing tag identification information if the tag identification information is the same as the tag identification information extracted by the extraction means, from the one or more response signals received by the reception means; 
 detection means for detecting strength of the response signal selected by the selection means each time the response signal is selected; and 
 informing means for informing whether a distance to the wireless tag specified by the specification means has shortened or increased according to comparison of strengths between each detection performed by the detection means. 
 
     
     
       2. The apparatus according to  claim 1 , wherein the informing means compares a strength detected currently and a strength detected previously by the detection means, and, when the currently detected strength is equal to or greater than the previously detected strength, informs that the distance to the wireless tag specified by the specification means has shortened, and, when the currently detected strength is smaller than the previously detected strength, informs that the distance to the wireless tag specified by the specific means has increased. 
     
     
       3. The apparatus according to  claim 1 , further comprising:
 an antenna configured to transmit the query signals via radio communication and receive the response signals; and 
 a handheld reader unit including the antenna and separated from an apparatus body. 
 
     
     
       4. A wireless tag detection apparatus comprising:
 a transmission section which transmits query signals to one or more wireless tags via radio communication; 
 a reception section which receives one or more response signals transmitted from the one or more wireless tags via radio communication based on the query signals transmitted via radio communication from the transmission section; 
 a specification section which specifies a wireless tag to be retrieved; 
 an extraction section which extracts tag identification information corresponding to the wireless tag specified by the specification section; 
 a selection section which selects a response signal containing tag identification information if the tag identification information is the same as the tag identification information extracted by the extraction section, from the one or more response signals received by the reception section; 
 a detection section which detects strength of the response signal selected by the selection section each time the response signal is selected; and 
 an informing section which informs whether a distance to the wireless tag specified by the specification section has shortened or increased according to comparison of strengths between each detection performed by the detection section. 
 
     
     
       5. The apparatus according to  claim 4 , wherein the informing section compares a strength detected currently and a strength detected previously by the detection section, and, when the currently detected strength is equal to or greater than the previously detected strength, informs that the distance to the wireless tag specified by the specification section has shortened, and, when the currently detected strength is smaller than the previously detected strength, informs that the distance to the wireless tag specified by the specific section has increased. 
     
     
       6. The apparatus according to  claim 4 , further comprising:
 an antenna configured to transmit the query signals via radio communication and receive the response signals; and 
 a handheld reader unit including the antenna and separated from an apparatus body. 
 
     
     
       7. A method of controlling a wireless tag detection apparatus, comprising:
 transmitting query signals to one or more wireless tags via radio communication; 
 receiving response signals transmitted via radio communication from the one or more wireless tags based on the query signals transmitted via radio communication; 
 specifying a wireless tag to be retrieved; 
 extracting tag identification information corresponding to the wireless tag specified; 
 selecting a response signal containing tag identification information if the tag identification information is the same as the tag identification information extracted from the one or more response signals received; 
 detecting strength of the response signal selected, each time the response signal is selected; and 
 informing whether a distance to the wireless tag specified has shortened or increased according to comparison of strengths between each detecting.